As is known, some systems, during the manufacturing process, require the application of one or more layers of material bonded together. Bonding processes utilize epoxy, glue, adhesive or other compounds, some of which are cured, for example, with exposure to certain wavelengths of electromagnetic radiation, or by applying heat.
During the bonding process, a void (or “bubble”) of unwanted gas or other material may be introduced to the system between a substrate material and another layer bonded to the substrate material. Such voids and their contents are particularly problematic in vacuum or near-vacuum applications and environments, where a volume of typically unwanted and undetected material, such as, for example, a gas, is contained within the void and becomes “trapped”. Such a gaseous volume in a void can expand when the system is placed under vacuum, or in a near-vacuum environment, such as, for example, space. Under ambient conditions such structures are often able to perform according to their intended standards without a deleterious effect. However, in low pressure environments including those approaching a complete vacuum, such unwanted pockets of gas can become unstable as they seek liberation from the layered structure. When this occurs, the layered structures are often damaged, which can adversely affect the performance of any component incorporating such damaged layered structures. When components are used in space, the resistive atmospheric pressure forces that would otherwise exert an inward pressure on layered structures having any gas-filled voids (for example, when the components are subjected to atmospheric pressures on Earth), are absent.
The expansion of the material contained in a void, as well as the presence of voids themselves, can reduce electrical contact, thermal contact, mechanical rigidity, etc. To complicate matters, voids or “bubbles” are difficult to detect during the manufacture and assembly process. Further, even if detected, such voids are also difficult to repair, especially after the bonding material in a bonding layer has dried or cured.
Layered structures that are bonded together, and devoid of “bubbles” would be desirable, particularly when such layered structures are used in components in an extremely low-pressure or vacuum environment, such as, for example, space.